Tbh i would start with a normal 4-4-2 and go from there.
Decide what style you want to play. City have a big pitch so i would play quick direct football and spread it down the wing.
Use TTF to get individual PI's and tweak them throughout your home games to develop a good home tactic.
e.g. TTF states mixed/short passing for DM but he may be misplacing them so give him more direct passing.
Then you have a home tactic.
When away from home ... keep the same formation but tweak the style if on a smaller pitch e.g. push up, play offside...mixed/short passing, mixed emphasis and however quick you want.
Eventually your players will gel to it.